1. Field of the Invention
This invention relates to certain poly(alkylene)ether polyol-based grafted resins, curable by free radical initiation, and having improved impact, and cure-through-volume properties as well as good over-all properties. More specifically, it relates to resins which may be viewed as a reaction product of grafted poly(alkylene)ether polyols with, e.g., methacrylate-capped aromatic diisocyanates.
2. Prior Art
It is known that curable anaerobic resins having desirable properties may be prepared as the reaction product of an organic polyisocyanate and an acrylate ester having an active hydrogen in the non-acrylate portion of the ester. Such resins are disclosed in U.S. Pat. No. 3,425,988 to Gorman et al. This patent relates specifically to monofunctional, acrylate-terminated material which is reacted with organic polyisocyanate in such proportions as to convert all of the isocyanate groups to urethane or ureide groups. The acrylate esters are preferably the acrylates and methacrylates containing hydroxy or amino functional groups on the non-acrylate portions thereof.
It is also known that poly(alkylene)ether glycols may be reacted with organic isocyanates to form urethane prepolymers which are subsequently cured by reaction with an active hydrogen molecule, e.g., with alcohols, amines, water, or other agents. Such systems are two-part systems, that is, the alcohol or amine must be kept separate from the prepolymer until the time of actual use since the mixed system has very limited pot life. As would be expected, the mixing of these viscous liquids leads to problems of nonhomogeniety and therefore imperfect cure, as well as causing substantial inconvenience. Similar urethane coatings curable through the action of moisture are also known, but have the defect that cure begins as soon as the coating is spread, thereby interfering with control of the coating operation and causing inconvenience.